Nowadays, due to the rapid development of science and technology, many products on the market are designed with many micro-hole structures, and laser micro-machining technology is widely used in 3C electronics, smart wear, cell phones, medical and other industries.
These holes on the products have the characteristics of tiny size, dense quantity and high processing accuracy requirements. With its high intensity, good directionality and coherence, laser micromachining technology, through a specific optical system, can focus the laser beam into a spot of several microns in diameter, and its energy density is very highly concentrated, the material will quickly reach the melting point and melt into molten material, and as the laser continues to act, the molten material starts to vaporize, producing Fine vapor layer, forming a state of vapor, solid and liquid co-existence. During this period, due to the vapor pressure, the melt is automatically sputtered out, forming the initial appearance of the hole. As the laser beam irradiation time increases, the depth and diameter of the micro-hole increases, until the laser irradiation is completely finished, the melt that has not been sputtered out will be solidified, forming a recast layer, so as to achieve the purpose of laser unprocessing.
The process stages of laser micromachining
In the first step, the laser beam is directed at the workpiece, which begins to absorb the laser light energy. In the second step, the laser light energy is converted into heat energy and the workpiece starts to heat up rapidly; then the workpiece starts to melt locally, evaporates, vaporizes and splashes out; finally, the laser action ends and the remaining condensation forms the recast layer. The depth of the micro-hole produced by laser micromachining is positively correlated with the number of laser pulses and the taper of the micro-hole is negatively correlated with the energy of the single laser pulse. The number of laser pulses and the energy of a single laser pulse have an effect on the shape of the processed microvia. Therefore, laser micromachining technology can be used to obtain the desired results by selecting the right number of laser pulses and single pulse energy.
Laser micromachining methods
While the common serial processing of highly dense arrays of microvias can suffer from low processing efficiency and long processing times, laser processing of individual microvias is highly efficient. Laser beam splitters enable laser beam splitting and parallel processing, and the use of laser parallel processing technology can optimize and solve this series of problems. A variety of corresponding laser beam splitters have been developed in the market, such as spatial modulators, beam splitting prisms, etc.
Summary
With the increasing demand for micromachining of high precision products and mechanical components in the market, and the development of laser micromachining technology becoming more and more mature, laser micromachining technology will be more and more widely used in the processing of high precision precision products by virtue of its advanced processing advantages, high processing efficiency and less restrictive machinable materials, no physical damage and intelligent and flexible control.
